1. Field of the Invention
Embodiments of the invention generally relate to an apparatus and method for controlling the temperature of a substrate during fluid processing.
2. Description of the Related Art
The semiconductor processing industry relies upon several methods for depositing conductive materials onto substrates, such as silicon wafers or large area glass substrates, for example. More particularly, deposition methods such as physical vapor deposition, chemical vapor deposition, and electrochemical plating are commonly used to deposit conductive materials or metals onto substrates and into features. Another deposition method that has been used in the semiconductor processing industry is electroless plating. However, electroless plating techniques have presented challenges to producing uniform deposition of conductive materials.
One challenge with electroless deposition processes is that they are highly dependent upon temperature, i.e., if one portion of a substrate is as little as 1° C. warmer than another portion of the substrate, then the warmer portion of the substrate will experience a substantial increase in the electroless deposition plating rate as compared to the cooler portion of the substrate. This difference in the deposition rate in the warmer areas of the substrate causes uniformity variations, and as such, electroless plating processes have generally not been favored for semiconductor processing. However, if substrate temperatures could be properly controlled, electroless deposition could provide advantages to semiconductor processing techniques in areas such as seed layer repair, capping, feature filling, etc.
Another challenge with respect to electroless deposition cells is achieving effective backside sealing. The electroless deposition chemistry generally has surfactants and other constituents that tend to diffuse to the back of the substrate, resulting in contamination and/or deposition on the backside of the substrate. As such, there is a need for an electroless deposition cell configured to control substrate temperature such that a uniform electroless deposition process may be conducted and prevent surfactants and other processing chemicals from contacting the backside of the substrate.